Painted steel substrate for cold-rolled substrate, hot dip galvanized substrate and electro-galvanized substrates. The coating types can be divided into a polyester, silicone modified polyester, vinylidene poly vinylidene fluoride and plastisol. Painted steel surface state can be divided into coated plates, embossing plate and printing plate, color coated steel is widely used in building appliances and transportation industries, the construction industry is mainly used for steel plants, airports, warehouses and frozen industrial and commercial roof of the building wall and door, civil uses less of the color plate. It steel distinction lies in the composition of the material type. Magnet can suck. Strictly speaking, steel and color-coated steel in metallic and surface treatment, and can not distinguish, because much the same; market distinction in the profile structure.